human dynamo vs worker

human dynamo and worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
human dynamo	Yes	No	No	No
worker	Yes	No	No	No

As nouns, worker is a hypernym of human dynamo; that is, worker is a word with a broader meaning than human dynamo:

Other hypernyms of human dynamo include actor, doer.

human dynamo (noun)	worker (noun)
a highly energetic and indefatigable person	sterile member of a colony of social insects that forages for food and cares for the larvae
	a person who works at a specific occupation
	a member of the working class (not necessarily employed)
	a person who acts and gets things done